The Royal Artillery Factory of La Cavada was an artillery foundry was established in 1622 by Jean Curtius with the support of Gaspar de Guzmán, Count-Duke of Olivares. It became fully operational 15 years later. Between 1637 and 1835 the facility was responsible for the production of more than 26,000 cannons for ships and fortresses throughout the Spanish Empire.
It closed after the defeat of the Spanish at the Battle of Trafalgar.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.